Metal carbides corrosion data

In several cases, materials for combined erosive and corrosive conditions have been evaluated on the basis of separate erosion and corrosion studies and data, with the consequence that the synergistic effects are left out of the evaluation. Since one or the other of these effects may be large, the conclusions may be quite wrong. For materials fliat usually are passive due to a dense oxide film, such as stainless steels, Wc is by definition very low. But since sand erosion more or less destroys the passive film, the corrosion rate increases strongly and may reach very high values, i.e. the contribution of Wce may be particularly high for these materials. The other synergy effect, Wec, is most pronounced for ceramic-metallic materials in which the metallic phase has inferior corrosion resistance, e.g. for a cemented carbide with a metallic phase of cobalt (WC-Co). 

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